One frustrating things about Antonio Cromartie is how limited he is despite his elite athleticism. He is excellent on vertical routes. Those are tests of pure athletic ability. Cromartie can hang with anybody. He is also good playing press coverage, where he gets to use his hands and his strength and dislodge a receiver from his center of gravity. A receiver must start again, which again turns a route into a test of pure athletic ability.
Cro struggles against anything else. He does not have good enough instincts to play zone effectively. The same goes when he plays off coverage. He must respond to receivers making cuts, which limits him.
Another frustrating part of his game is how inconsistent his technique is even when playing coverage tailored to his strengths. He does not always play with his hands and get physical when he should. If he ever did, no receiver would ever be able to get open on him. He does not, however.